The present invention is directed to an apparatus and method for use in manufacturing a semiconductor device including an input-output (IO) face having a plurality of IO lands. The semiconductor device is situated in an operating position with a mold for depositing solder ball connection structures to the IO lands for implementing controlled collapse chip connection (C4) IO connection structures. Such solder ball C4 connection structures are useful for such semiconductor devices as single-chip or multi-chip module packages. In particular, the apparatus of the present invention is directed to a fixture for use in selectively positioning a semiconductor device and a depositor in a manufacturing process, and for separating the semiconductor device and depositor to a separation distance while the semiconductor device and depositor are subjected to appropriate ambient conditions for effecting reflow of the solder material in the depositor. The method of the present invention includes the steps of separating the semiconductor device and the depositor to a separation distance after effecting initial reflow of solder to form interim solder balls, and effecting continued reflow (or a renewed reflow) of the interim solder balls to final solder balls free of imperfections impressed in the interim solder balls by contact with cavities in the depositor.
When using a depositor having a plurality of cavities containing solder material for wettingly applying the solder material to the IO lands of a semiconductor device, there is a need to ensure that no more than a predetermined distance separates the cavity bottom from the IO lands. A predetermined amount of solder is contained within each depositor cavity to produce the desired amount of solder on the IO land. If the distance between the cavity bottom and the IO land is too great, then the solder will not reach the IO land when the semiconductor device and the depositor are in the operating position and no solder deposition will occur. However, when there is an appropriate distance between the IO land and the solder material within the cavity (i.e., the cavity depth is appropriate for the desired amount of solder to be deposited on the IO land), then there is continued contact between the deposited solder and the depositor after solder deposition has occurred. Thus, in such situations, after reflow has formed the solder ball there is an impression of the depositor left on the solder structure. This impression precludes the solder structure's achieving a true solder ball configuration. Such untrue shape contributes to unpredictability in solder ball connection in C4 connection operations between the semiconductor device and other components.
What is needed is an apparatus and a method to ensure that solder depositions are reliably and repeatably effected when a depositor is used for depositing solder to a semiconductor device. There must be true solder ball depositions on the semiconductor device IO lands.